<!DOCTYPE html>
<html>
<head>
  <style>
  p { background:yellow; }
</style>
  <script src="http://code.jquery.com/jquery-latest.js"></script>
</head>
<body>
  <p></p>

<button>Call empty() on above paragraph</button>
<script>
  $("button").click(function () {
    $("p").empty();
  });
</script>

</body>
</html>